Scientists Just Pulled CO2 From Air And Turned It Into Coal

Caterpillar tractors collect black coal pile. Illustration of supply field of a power station. Credit: Getty

Getty

Scientists have discovered a breakthrough technology, a way to pull CO2 from the atmosphere and turn it back into coal. This new discovery has the potential to change the way we think about CO2.

The research, recently published in the journal Nature Communications, provides a step-by-step guide in turning CO2 into coal, acting to remove the greenhouse gas from the atmosphere and lock it away in solid carbon form.

Carbon sequestration, the act of removing carbon dioxide from the atmosphere and locking it away is a growing field aimed at mitigating climate change. Major oil and gas companies, like Shell, are spending billions of dollars to develop carbon sequestration plants that store CO2 in porous reservoirs within Earth. However, this approach is expensive as it requires CO2 to be compressed into liquid form and injected into rock formations within Earth. Due to cost, this approach is not economically viable without heavy subsidies and/or a carbon tax to help offset costs.

A schematic showing the use of liquid metal to convert CO2 into solid coal.

RMIT University

This recent development adds another method to efficiently lock away carbon dioxide in a safe and long term way. This isn't the first time scientists converted carbon dioxide into a solid form, however, previous techniques required extremely high temperatures making the approach not practical beyond a laboratory setting.

To convert CO2 from the atmosphere into solid carbon coal, the researchers used a cerium-containing liquid metal catalyst, which is uniquely efficient at conducting electricity and has specific properties.

When the researchers electrically charged a vessel with CO2 and the liquid metal, the carbon dioxide began to convert into small flakes of coal. The solid carbon flakes naturally detach from the liquid metal and fall to the bottom of the vessel, allowing for continual production of solid carbon from carbon dioxide. The end product can also hold an electrical charge, meaning it could be used as a supercapacitor after the process.

Carbon sequestration, the act of removing carbon dioxide from the atmosphere and converting it to a liquid or solid form, presents an appealing approach to mitigating climate change. As humans continue to emit carbon dioxide into the atmosphere, an inexpensive and large scale method to remove CO2 from the atmosphere would provide an ideal solution.

"While we can't literally turn back time, turning carbon dioxide back into coal and burying it back in the ground is a bit like rewinding the emissions clock," RMIT researcher Dr. Torben Daeneke said in the press release.

The international research team from Germany, China, the United States and Australia believes this is a first step toward an abundant and inexpensive method to remove carbon dioxide from the atmosphere and repurpose it as solid coal.